High conductivity and high density proton conducting Ba1−xSrxCe0.5Zr0.35Y0.1Sm0.05O3−δ (x = 0.5, 0.7, 0.9, 1.0) perovskites for IT-SOFC

Abstract

Solid oxide fuel cell (SOFC) has been achieving attention in term of possibility in variety of fuels. Proton conductor enhanced conventional oxide conducting electrolyte has become more and more interesting particularly in intermediate operating temperature. Combination of doped BaCeO3 and BaZrO3 by doping Sr, Y and Sm was studied as the series of Ba1−xSrxCe0.5Zr0.35Y0.1Sm0.05O3−δ (BSCZYSm) by varying composition x = 0.5, 0.7, 0.9 and 1.0. The X-ray analysis reveals right-shifted peaks due to changing in unit cell volume. The cell parameters and density decreased with increasing Sr content. Rietveld refinement shows that all compositions crystallize in the cubic symmetry in the space group Pm-3m. Thermogravimetric analysis on dried and hydrated samples under nitrogen show significant weight change to prove the proton uptake at higher temperature. Scanning electron microscopy shows that the density is higher than 90% for all samples. BSCZYSm with x = 0.5 shows the highest conductivity in wet argon condition which is 2.391 × 10−3 S cm−1 at 700 °C. Particle size of materials were examined and reveal average diameter of 5.8 μm approximately.